This invention relates to faceplate combinations.
Circuit packs to be mounted in shelves have faceplates at front edges of printed circuit boards of the packs, the faceplates lying side-by-side across the fronts of the shelves to provide substantially continuous walls. The printed circuit boards in a shelf are interconnected either between themselves or with other electrical, electronic or optical equipment outside the shelf through a back or mid-plane of the shelf. In addition, in order to enable the printed circuit boards to perform their desired functions, electrical or optical connections are required through the faceplates to outside electrical or optical equipment. These connections are made through connector units carried by the faceplates. These connector units comprise connectors joined directly together at faceplates or connectors which are interconnected by electrical or optical adaptors carried by the faceplates. For mounting to the faceplates, carriers holding adaptors or connectors may be mounted upon the faceplates. An example of such a structure is described in U.S. Pat. No. 5,949,946, granted to G. Debortoli et al, on Sep. 7, 1999.
While printed circuit boards are designed to provide certain functional requirements directly upon commencement of use, it is now becoming more common to design printed circuit boards not only for their immediate use capabilities, but also to enable them to have their functional requirements modified at some future time, e.g. perhaps to affect the functional requirements of their shelves. In this regard, a printed circuit board for instance may be designed for initial use without a daughter board, but has the provision to carry a daughter board at some future time thereby increasing the number of terminals for connection to outside sources or equipment.
Obviously, change in functional requirements to a printed circuit board under the above circumstances, as it occurs after some use, needs to be effected in the field. Typically to effect functional change, an xe2x80x9cupgrade kitxe2x80x9d is sent to the field, such a kit including, for each printed circuit board that requires modification, a new faceplate to replace the existing faceplate. The new faceplate differs basically from the existing faceplate in that it is designed to carry more connector units than the existing faceplate, for the purpose of providing access for more interconnections from printed circuit board terminals to outside sources or equipment. Thus the existing faceplate, after removal, is likely to become a scrap item while the new faceplate creates additional expense, together with the original expense incurred in the design of the new faceplate.
In addition, the time taken to effect modifications to a printed circuit board in the field tends to be inordinately lengthy. Conventionally, this involves forward movement of a circuit pack in its shelf to provide access, disconnection of connectors from the faceplate (rear access to the faceplate being required for this latter purpose), and disconnection of elongate transmission elements, i.e. optical or electrical cables or wires, from printed circuit board terminals. This results in the further expense of replacing existing items with new items of the circuit pack and an inconvenient number of such items may be involved. This increases the difficulty and time required for the modification process and also increases the possibility of unattached items becoming mislaid (thus adding to further down time, or even the potential hazard of losing small items within the shelf itself, which could lead to electrical or optical malfunction or structural damage.
Further, the tools required for present printed circuit board modification procedures may, if carelessly or inappropriately used, cause damage to circuitry on a board, particularly during the stages of removal and replacement of a faceplate, and of providing access to the rear of the faceplate for connector or adaptor removal. The only known way to limit or avoid some of the above problems is to completely replace a circuit pack with a new pack which includes the necessary differences to effect modification in performance.
The present invention seeks to mitigate or lessen the above problems.
According to one aspect of the present invention, there is provided, in combination, a faceplate and a cover, wherein:
the faceplate has a front side and a rear side and opening means extending from the front to the rear side of the faceplate; and
the cover is provided for location in a position over at least a part of the opening means with the cover being capable of being removed from the at least one part of the opening means to enable the in-series interconnection of two elongate transmission elements through the at least part of the opening means, a first of the transmission elements extending rearwardly from the faceplate and a second of the transmission elements extending forwardly from the faceplate.
In one arrangement of the inventive combination, the cover is provided by a connector unit as will be described. In another arrangement the cover is sufficiently large to completely close the opening means.
It is to be understood that in the latter paragraph, and throughout the remainder of the specification and in the claims, the term xe2x80x9cconnector unitxe2x80x9d is intended to include structures incorporating either a) optical or electrical connectors or b) adaptors for interconnecting such connectors, unless specifically stated otherwise. Also, the term xe2x80x9cconnector meansxe2x80x9d as to be later used throughout the specification and in the claims, is intended to include such connectors or adaptors, unless specifically stated otherwise.
The above combination according to the invention has the advantage that the faceplate may itself be designed for any future modification which may be required by a circuit pack of which the faceplate is to form a part. In an arrangement with a connector unit providing the cover, the connector unit has a structure to enable a future modification to be made. In this arrangement, the connector unit has two regions, one of the regions being closed and the other of the regions having a port. The connector unit is for mounting in a mounting station in which the closed region provides the cover for part of the opening means. The port of the other region is directed to face through another and open part of the opening means for the in-series interconnection of two other transmission elements through the port, with one of the transmission elements extending rearwardly and the other transmission element extending forwardly from the faceplate. However, upon it being required to modify the operation of a printed circuit board, then this may be effected, importantly, without removal of the existing faceplate (together with avoidance of extra cost, downtime involved, and risk of damage to equipment), and without its replacement with a new faceplate having more access for connection to the printed circuit board.
In the arrangement using a connector unit with a closed region, a second connector unit may also be included. This second connector unit has two regions corresponding in position to the two regions of the first connector unit. The second connector unit may replace the first connector unit and a port provided in each of the regions of the second connector unit is directed to face through the opening means. Each port is individually provided for the in-series interconnection of two transmission elements. Thus, replacement of the first with the second connector unit upon the faceplate increases the number of elongate transmission elements which extend from in front of the faceplate and may be connected through the faceplate to the circuit board.
In the arrangement having a cover which completely covers the opening means, a connector unit may be provided having two regions, one or both of which is provided with a port, similar to either the first or second connector unit described above. It follows that for modifying the operation of the associated circuit pack, the cover may be completely removed and be replaced with either the first or second connector unit to enable two elongate conductor elements to be interconnected in-series through the or each port of the connector unit for connection to the circuitry.
It follows from the above two arrangements of the invention that the same faceplate with the opening means, as discussed, may be employed for at least one and possibly more modifications to be made to the circuitry and thus to the operation of the circuit pack. Hence, a replacement faceplate normally required for this purpose, together with its attendant cost and possible problems in the replacement procedure, is avoided.
In a preferred construction, quickly releasable means is provided which is co-operable between the faceplate and the connector unit for mounting the connector unit to the faceplate.
Conveniently, the quickly releasable means comprises a latching arrangement. With the latching arrangement, small items of assembly (e.g. screws etc.) are avoided together with tools necessary for their assembly and disassembly. Any potential problems associated with loss of such small items, particularly within the confines of a circuit pack, or within a shelf, are thus avoided.
In a further preferred construction, the latching arrangement includes a plurality of mounting flanges on the front side of the faceplate. With such an arrangement, the mounting plates are accessible from the front side for mounting a connector unit in a mounting position on the faceplate. Hence, the connector unit may be mounted simply upon the front side of the faceplate using the latching arrangement thereby avoiding the need for rear access to the faceplate for connector unit assembly purposes.
The invention also includes, in combination, a faceplate and a connector unit wherein:
the connector unit has at least one port for the in-series interconnection therethrough of two elongate transmission elements with the transmission elements extending in opposite directions from the connector unit; and
the faceplate has a front side and a rear side, the rear side provided for connection with a printed circuit board, the faceplate also having opening means extending from side to side of the faceplate and also having a mounting structure located on the front side of the faceplate, the mounting structure accessible from the front side for mounting the connector unit in a mounting position on the faceplate with the at least one port facing in a direction through the opening means.
In addition, the invention includes a connector unit comprising a connector means and a carrier, the carrier having a base carrying the connector means and a plurality of latches provided by flanges extending resiliently from the base.
The invention also includes a method of modifying the operation of a circuit pack. In this method, a faceplate has a cover which closes opening means against transmission of electromagnetic signals through the opening means. The method generally comprises removing the cover and then interconnecting in series through the opening means, two elongate transmission elements to be connected to circuitry of the pack with one transmission element extending forwardly and the other transmission element extending rearwardly of the faceplate. Alternatively, a method is provided according to the invention in which a first connector unit is mounted to a faceplate, the connector unit having a port facing through the opening means and a region which is closed and covers part of the opening means. The first connector unit is replaced with a second connector unit having two ports, one of the ports corresponding in position to the closed region of the first connector unit. Each port of the second connector unit is used individually to interconnect in series two connector elements to be connected to the circuitry.